OTHER LIABILITIES (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Current:
Deferred revenue	$ 28,065		$ 9,451
Legal provisions	629		635
Derivative instruments	1,259		0
Operating lease liability	3,437		3,203
Other	198		226
Total other current liabilities	33,588		13,515
Non-current:
Deferred tax liabilities	20,312		21,294
Derivative instruments	10,873		12,670
Operating lease liability	7,606		8,434
Related party Guarantee Fee payable (Note 4)	33,465		33,465
Other	4,453		4,137
Total other non-current liabilities	76,709		$ 80,000
Deferred Revenue, Revenue Recognized	$ 3,400	$ 2,800